I've encountered a NullPointerException when running RealignerTargetCreator. I wasn't able to find any hint that that's a known problem, so I'm posting it here (sorry, should I have overlooked something).

This is in regards to a small exome capture experiment that I'd recently talked about here: http://gatkforums.broadinstitute.org/discussion/3531/bam-index-files-from-1000g-not-recognized-other-questions#latest . There are 8 experimental BAMs and 22 BAMs from 1000G supplied as inputs to HaplotypeCaller. And it quits with a code exception error at 52.1%. I've attached the relevant output. Also attached is the input files list. My OS info is:

When trying to run the HaplotypeCaller in 2.6.2 with -nct I'm getting a number of crashes. Is NCT currently supported or is this experimental for the HaplotypeCaller currently? With the Multithreading I'm not exactly sure where the error is occurring and it's a pretty big bam. If needed I can try to narrow it down a bit further and create a subset bam...

##### ERROR ------------------------------------------------------------------------------------------
##### ERROR A USER ERROR has occurred (version 2.4-9-g532efad):
##### ERROR The invalid arguments or inputs must be corrected before the GATK can proceed
##### ERROR Please do not post this error to the GATK forum
##### ERROR
##### ERROR See the documentation (rerun with -h) for this tool to view allowable command-line arguments.
##### ERROR Visit our website and forum for extensive documentation and answers to
##### ERROR commonly asked questions http://www.broadinstitute.org/gatk
##### ERROR
##### ERROR MESSAGE: There was a failure because temporary file /tmp/org.broadinstitute.sting.gatk.io.stubs.VariantContextWriterStub1033673347640679118.tmp could not be found while running the GATK with more than one thread. Possible causes for this problem include: your system's open file handle limit is too small, your output or temp directories do not have sufficient space, or just an isolated file system blip
##### ERROR ------------------------------------------------------------------------------------------

The file is actually there, and is gzip-compressed and vcf-formatted.

However, if I specify -o output.vcf instead of -o output.vcf.gz, then everything works. I suspect the problem is with the autodetection of the codec. In VariantContextWriterStorage, LocalParallelizationProblem is thrown not only if the tmp file cannot be found, but whenever a FeatureDescriptor cannot be found for the file.

So... It seems like compressed output cannot be used from threaded processing with UnifiedGenotyper. Is my assessment correct?

A better error message would be helpful to prevent others from trying the same thing I did.

It would be nice to be able to write compressed output from a threaded UnifiedGenotyper, perhaps: a) the temp file could be written uncompressed even though the final file will be compressed, or b) the Codec-detection could detect gzip-compressed files?